Device for brazing



Dec. 8, 1931. F MJYUN'G l,835,624

DEVICE FOR BRAZING Filed Jan. 26. 1931 2 Sheets-Sheet 2 /7206725 .2 ?x d %fazz aga Patenta& 8, 1931 UNITED STATES PATENT OFFICE FRE!) M. YOUNG, OF WISCONSIN'- DEVIO'E FOB BRAZING Application filed January 26, 1931. Serial No. 511334.

'This invention relates to methods and in space heaters are frequently subjected to apparatus for brazing, hard soldering, or considerable steam pressure within the tubes, performing similar Operations in the joining and if the temper has been drawn from the of metal parts, especially-the joining of parts end portions of the tubes by overheatng on of heavy section to parts of lighter section, being brazed to the header plates, there is a such as the tubes and header sheets of unit likelihood of the tubes being of insufiicient heaters built of copper and similar sheet strength for the intended steam pressure. metals. This results in the likelihood of the tubes The main object of this invention is to probulgng at the places where they were sub- 10 vide suitable apparatus for making jomts jected to such excess temperatures and conseby brazing, especially where one of the parts quently reducing the air space between the consists of thin tempered metal to be connecttubes and decreasing the efliciency of the heated to a heavier part, and which permits the er by interfering with the intendedflow of air use of temperatures at the joint which closely between the tubes.

15 approach the fusing point of the metals The apparatus shown is designed for supjoined without endangerng the strength or portin heater cores during the brazing operdrawing the temper from the thinner metal ation t ereof, and includes means for subjectpart ad acent the joint, and also permits the ing the tubes to a draft of cooling air sufliuse in such work of spelters or solders having ciently near the ends thereof to hold at safe 20 a melting point which closely approaches the temperature all portions except those portemperature of fusion of the metals which tions which are within and being joined to the are joined. A further object is to provide header plates. The apparatus is also providmeans for rapidly cooling the thnner part -ed with additional intake nozzles suitably adjacent the brazed joint to dissipate heat located for drawing off the fumes created by 25 therefrom at proper rate to prevent injury the brazing torch and spelter. from overheatng without however interfer- The drawings show supports 1 and 2 for ing .with the brazing operation. A further the cores 3, upon which the brazing operaob ect is to provide apparatus of this kind tions are to be performed. The cores 3, as ilwhich will at the same time draw ofl the lustrated ,consist ofabank of copper radiator 30 fumes arising from the brazing operation. tubes 4 having their ends seated n apertures The purposes of the invention are accom- 5 in the header plate 6, and having their body plished by the method and apparatus illusportions connected together by the usual fin trated in the drawings, in which: plates '13.

F igure 1 is a side elevation of a brazing The header plates and tubes may be of 35 stand designed for use in brazing copper rahard copper having approximately the same diator tubes to the header tube sheets, apair fusing temperatures but the header plates are of radator cores being shown in position usually about twice the thiclmess of the tube thereon. walls. In order to insure a good joint where Fig. 2 is an end view of the same. i the tubes fit the apertures 5, the two are 40 F ig. 3 is an enlarged fragmentary detail, brazed together with a spelter or hard solder partly in section, illustrating the relationhaving a fusing point not greatly below that ship between a brazing torch, the article of the tubes and header plates. operated upon, and the air suction nozzles. A torch is indicated at 7 for use in per- The improved method and apparatus as forming the brazing operation. The heat 45 herein illustrated and described is designed from this torch is localized at the joint by x for use in connection with the manufacture creating a strong draft of cooling air around .of heat transfer unitsmade up of tempered. the tubes just below the header plate 6. thin copper tubes assembled with transverse For. the purpose of creating the desired fin sheets and having their ends connected to flow of air, blower -8, driven by belt 9 and 50 header plates. These structures when used motor 10, has an intake conduit 11 termiare cooled by a draft l claims. A

' means having nating in the intake nozzles 12, the months of which extend along the sides of the upper ends of the heater cores 3. By this means a draft of cooling air is drawn through the radiator between the fins 13 thereof, and around the tubes 4 near their upper ends just below the header plate 6, where the brazing operation -is performed. 'The heat of brazing is in this manner joint'and cannot afiect thestrength and temper of the tubes below the header plate.

In order to have eflicient heat transfer when in service, the tubes are made as light as possible in View of the pressures to which they are to be subjected, a usual proportion being a thickness of .02 inches for the" tube stock and .05 inches for the header plate.

The conduits 11 have branch nozzles 14,

the months 15 of which are above the articles operated upon, in position for drawing o& the fumes which are generated during the brazing or soldering Operations.

In practicing the invention, the blower is driven at the speed required for properly cooling the work operated upon according to the character of the brazing or soldering operation. If spelters or solders are employed which fuse at a comparatively high temperature, heat is applied accordingly by means of a torch 7. In order to prevent the heat from traveling down the tubes 4, at a rate sufiicient to injure the tubes, the latter of air induced therearound as indicated by the arrows in the drawings. By means the apparatus shown, it is possible to attain strong joints without harmful eflects upon the articles of work. In practice with metal of the thickness mentioned above, I have found the best results with an air velocity through the core at the suction nozzle of about 2000 feet per minute.

It will be understood that the apparatus herein described may be modified with respect to .various. details without departing from the invention as defied I claim:

1. An apparatus for brazing the header sheets and tubes of radiator cores comprising a support for holding a core with its. header sheet at the top, an air blast nozzle positioned' at' one face of the core adjacent and below the header sheet and means for creating an *air flow at said nozzle.

2. An apparatus for brazing the header sheets and tubes of radator cores comprising 'a support for holding a core with its header sheet at the top, and air exhausting rent of air across the tubes.

3. An apparatus for brazng the header localized to near the by the 'followa nozzle located immediately below said header sheet for drawing a cur-` sheet at the top, and air exhausting means having a pair of nozzles located one immediately below said header sheet for drawing a current of air across the tubes, and the other above and spaced from said tube sheet. Signed at Racine this 23rd day of January,

FRED M. YOUNG.

of this. method and 

